Nutrition for gaining weight

Hi everyone!
I'm 21 year old 5'3" female and weigh around 101 lbs. I'm looking to gain a little bit more weight but want to hold off on gaining FAT.
I know most people on here are on Paleo/PB to lose weight and I see that a lot of people are eating 1700 cals or below.
Right now, I'd say I eat around 2000 most days, do weight training 3-4 times a week and do some cardio as well.
I do fairly strict Paleo (except I eat full-fat Greek yogurt almost every day). Most of my calories are from fat, then protein, and carbs last. I eat anywhere from 80-120 g of carbs a day.
However, I find that I get hungry really quickly, even after a big meal. I usually snack on fruits and nuts but am still occupied by thoughts of when my next meal is going to be. Since I'm slightly underweight, should I listen to my body and just eat whenever and however much I want? Of course, I will stick to Paleo foods.
I would just like some advice on how many calories I should be taking in to see gradual weight gain, how to prevent FAT gain, and if there are certain foods that should be emphasized. I'm a college student so my workouts are pretty much set and am limited in what I can bring to school from home.
Thanks!!

I have a similar problem. I am underweight and even more so on primal diet. The only advice that I've seen on previous posts was: eat more calories with more fat.
For me it's not as easy as it sounds. My stomach doesn't like too much diary. I tried eating lots of nuts, but recently I stopped because of fitic acid.
Yesterday I tried eating a plate of cooked vegetables mixed with half a glass of coconut oil. It was actually quite tasty, but later on I didn't feel well.
I don't know if I am on the right track, but I keep trying...

If you want to gain weight, you have to eat more food.. no way around it.. I've found upping my intake of avocado, taking olive oil shots, & squeezing in huge carb intake meals twice a week are good for putting on some lbs (refeeds).. Bananas, & yogurt can put some weight on me too.. Just have to eat more primal food, with a focus on fat, (to keep it primal) all there is to it.. I personally eat 6 eggs a day.. (eggs are cheap & loaded with nutrients & calories)

of course, strength training & lifting heavy is key to "put some meat on your bones".. rest 2-3 minutes between sets (I personally rest 4-5 min between sets) & no cardio, & sleep better, take naps, try to calm down all together.. preserve energy.. Eat more energy than you burn

Let me know if you have any questions.. I've battled the same thing you're going through..

Changing nutrition won't cause gains to be in muscle instead of fat unless you happen to be protein deficient or something. To gain muscle you'll need to work your muscles (and provide them with the protein they need to repair themselves of course).

Changing nutrition won't cause gains to be in muscle instead of fat unless you happen to be protein deficient or something. To gain muscle you'll need to work your muscles (and provide them with the protein they need to repair themselves of course).

+1 Once you are fully grown, your body won't add muscle, unless it is done as an adaptive response to stimuli/stress

Hehe, yep, this is how I gained all that weight. You could also try being Hispanic, we really don't have issues when it comes to gaining weight.

white rice, white potatoes cut like french fries and fried in coconut oil (refined, so you don't get the coconut taste), steak also cut in strips and also fried in coconut oil, sauteed tomatoes and some cilantro. Where I come from, we call that "lomo saltado" and it's a staple dish, it's delicious, but the potatoes + rice + fat is a sure-fire way to get some weight.

Sprint once weekly, uphill, that will keep the fat gain lower while still building muscle.